In the present study, we have developed an isolated perfused rat kidney model to examine the direct effects of ET and LT on renal function. This model will allow investigation of the toxins renal effects independent of their potential influence on systemic hemodynamic function. The model will permit measures of the effects of ET and LT on glomerular filtration rate; tubular function including sodium and glucose excretion as well as reabsorption, concentration and acidification; and interstitial changes. Studies are underway focusing on the effects of ET in the isolated kidney model.